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Measuring the Densities of Aqueous Glasses at Cryogenic Temperatures
Published on: June 28, 2017
Computing the viscosity of supercooled liquids.
Akihiro Kushima1, Xi Lin, Ju Li
1Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
The Journal of Chemical Physics
|June 18, 2009
Summary
This study introduces a new atomistic method to calculate liquid viscosity using activated state kinetics. The approach accurately models high-viscosity liquids, bridging molecular dynamics and experimental observations.
Area of Science:
- Computational Physics
- Materials Science
- Chemical Engineering
Background:
- Calculating the viscosity of highly viscous liquids is computationally challenging.
- Existing methods struggle with long relaxation time processes characteristic of these materials.
Purpose of the Study:
- To develop an atomistic method for computing viscosity in highly viscous liquids.
- To model transport phenomena beyond the reach of current molecular dynamics simulations.
Main Methods:
- Utilized a basin-filling algorithm to explore energy landscapes and generate transition state pathways.
- Developed a Markov Network model within the Green-Kubo formalism for viscosity computation.
- Derived a mean-field description with a coarse-grained activation barrier.
Main Results:
- The method accurately reproduces temperature dependence in both low- and high-viscosity regimes (10^2–10^12 Pa s).
- Successfully modeled the fragile behavior observed in glass-forming liquids.
- Provided insights into the fundamental differences between strong and fragile liquids.
Conclusions:
- The proposed method offers a novel approach to studying long relaxation time processes in viscous liquids.
- This work enhances our understanding of liquid dynamics and transport phenomena at an atomistic level.
- It lays the groundwork for future studies on diverse liquid systems, including strong liquids like silica.
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